Sensitizing dyes containing a 2-thio-2, 5 (3, 4)-thiazoledione nucleus



Patented Oct. 20, 1953 SENSITIZIN G DYES CONTAINING A Z-THIO- 2,5 (3,4) -THIAZOLEDIONE NUCLEUS Roy A. Jeifreys and Edward B. Knott, Harrow,

England, assignors to Eastman Kodak Company, Rochester, N. Y., a corporation of New Jersey N Drawing. Application December 29, 1950, Serial No. 203,526

12 Claims.

This invention relates to merocyanine dyes containing a 2-thio-2,5(3,4)-thiazoledione nucleus and to methods for preparing them.

Merocyanine dyes containing a 2-thio-2,4(3,5) thiazoledione (rhodanine) nucleus have long been known. Some of these dyes have been found to be quite useful in increasing the sensitivity of photographic silver halide emulsions.

We have now found an entirely new class of merocyanine dyes which are quite useful as sensitizers for photographic silver halide emulsions.

It is, therefore, an object of our invention to provide a new class of merocyanine dyes. A further object is to provide methods for preparing these new dyes. Still another object is to provide photographic silver halide emulsions sensitized with these new dyes, and methods for preparing these emulsions. Other objects will become apparent from a consideration of the following description and examples.

According to our invention, we provide new merocyanine dyes represented by the following general formula:

R. .above, as well as cyclopropyl, cyclobutyl, (especially cyc1oin the cycloalkyl ring), L represents a methine group (substituted and unsubstituted, e. g,., =CH, =CR-- where R, represents an alkyl group, such as methyl, ethyl, etc.), n represents a positive integer from 1 to 2, 03 represents a positive integer from 1 to 3, and Z represents the non-metallic atoms necessary to complete 'a' heterocyclic nucleus containing from 5 to 6 atoms in the heterocyclic ring, such as those selected from the group consisting of those of the thiazole series (e. g. thiazole, 4-methylthiazole, ll-phenylthiazole, 5-methylthiazole, 5-phenylthiazole, 4,5- dimethylthiazole, 4,5-diphenylthiazole, 4-(2- thienyl) thiazole, etc.), those of the benzothiazole series (e. g. benzothiazole, 4-chlorobenzothiazole,

' ethoXy-fi-naphthothiazole,

. methoxybenzoselenazole,

iodobenzothiazole, 4 ethoxybenzothiazole, 5-

ethoxybenzothiazole, tetrahydrobenzothiazole, 5,- 6-dimethoxybenzothiazole, 5,6-dioxymethylenebenzothiazole, S-hydroxybenzothiazole, 6-hydroxybenzothiazole, etc.), those of the naphthothiazole series (e. g. a-naphthothiazole, ,B-naphthothiazole, 5-methoxy-,B-naphthothiazole, 5- 8-methoxy-a-naphthothiazole, 7-methoxy-u-naphthothiazole, etc.), those of the thionaphtheno-T,6,4,5-thiazole series (e. g. 4-methoxythionaphtheno-7,6',4,5- thiazole, etc.), those of the oxazole series (e. g. -methyloxazole, 5-methyloxazole, 4-phenyloxazole, 4,5-diphenyloxazole, i-ethyloxazole, 4,5-dimethyloxazole, 5-phenyloxazole, etc.), those of the benzoxazole series (e. g. benzoxazole, 5-chlorobenzoxazole, 5-methylbenzoxazole, 5-phenylbenzoxazole, G-methylbenzoxazole, 5,6-dimethylbenzoxazole, 4,6-dimethylbenzoxazole, 5-methoxybenzoxazole, fi-ethoxybenzoxazole, 5-chlorobenoxazole, S-methoxybenzoxazole, 5-hydroxybenzoxazole, G-hydroxybenzoxazole, etc.), those of the naphthoxazole series (e. g. a-napthoxazole, fl-

napthoxazole, etc.), those of the selenazole series (e. g. 4-methylselenazole, 4-phenylselenazole, etc.), those of the benzoselenazole series (e. g. benzoselenazole, 5-chlorobenzoselenazole, 5- 5-hydroxybenzoselenazole, tetrahydrobenzoselenazole, etc.), those of the naphthoselenazole series (e. g. a-naphthoselenazole, p-naphthoselenazole, etc.), those of the thiazoline series (e. g. thiazoline, 4-methylthiazoline, etc.), those of the 2-quino1ine series (e. g. quinoline, 3-methylquinoline, 5-methylquinoline, 7-methylquinoline, S-methylquinoline, fi-chloroquinoline, B-chloroquinoline, 6-methoxyquinoline, fi-ethoxyquinoline, 6-hydroxyquinoline,

S-hydroxyquinoline, etc.) those of the 4-quinoline series (e. g. quinoline, fi-methoxyquinoline, 7- methylquinoline, 8-methylquinoline, etc.), those of the l-isoquinoline series (e. g. iscquinoline, 3-,4-dihydroisoquinoline, etc.), those of the 3- isoquinoline series (e. g. isoquinoline, etc.), those of the 3,3-dia1kylindolenine series (e. 'g. 3,3-dimethylindolenine, 3,3,5-trimethylindolenine, 3,- 3,7-trimethylindolenine, etc.), thoseof the pyridine series (e. g. pyridine, 5-methylpyridine,v

, etc.), etc.

by the following general formula? II z R-1(="on om; o -L=L N-R, 1'1.

wherein R, L, Z, and n have the valuc's sfi roan.

above, R2 represents a hydrogen atom, an alkyl group (e. g. methyl, ethyl, etcll}. or'tlie'acyl group of a carboxylic acid (e. g. acetyl, propionyl etcd). R3 represents an aryl group (e. g. phenyl, m-, and p-tolyl, etc.), or R2 and Re together represent the non-metallic atoms necessary tie-cone plete a heterocyclic nucleus (e. g. a piprldyl, morpholinyl, etc. nucleus) p represents'a positi-ve integer from 1 to 2, and X1 represents an acid radical. e. g. C1-,.Br,.I-,-C2H5SO-4r,.

p=cnicemsoe- SCN etc., with; a zgtnio-aakm tiliazoledib e compound selected from those represented by the following general formula:

where d is 1- can bepr-epared by condensing a cycla-mmonium quaternary salt selected from those representedby the following general formula:-

above, and R4.- feoreserits an alkylgrooe', suchas methyl; ethyl, etc, Oran aryl group, such as phenyl 0-, m and p tolyl, etc,- with a 2-"thio'- 2,5814)- tniazoiedmne selected from those-rema sented by Formula m above. The eondensaticns: can-advantageously be carried out in the presefic'e' of a basic condensing agent, such its the tfiaikyiamirres- (e. g. triethylami'ne; m ximum etc dialkyiarii-Iirres (e. N,-N=diiiietliyI-; and mfimet'hynniune, etc) heterocyclic tertiary amines (e. g. pyridine; quiiiolii ie', N-alkylpiperidii'ie's, etc) alkali metal alcoholate's e. gtso'dium' nietnyiate, s'odi um' tl'iylait'e, etc.)',-

The com dns'dtioziS-cari also be carried.- come the presenceof an inert diluent; such a ethanol, ethanol,- moropanol, isoeropanci. ii-bii'tar' io'l, isobutanol, dithyl ether, acetone, 13-416mm; etc.

The following examples will serve to illustrate fully manner whereby we practice our, invention.

4 Example 1.-[2 (3 methylthiazoline) [4 (3- methyl 2 thz'o 2,5(3,4) thiczzoledionen dimethinemerocyanine 1*.9'5? g. off fi -acetanilidovinylthiazoline methiodide and"0'.73 g. of. 3-methy1-2-thio-2,5 (3,4)- thiazoledione (Cook et al., Jour. Chem. Soc. (19499 23411) were mixed with 8 cc. of ethanol and 031cc;- of triethylamine, and the reaction mixture was refluxed for 20 minutes on a steam bath. The reaction mixture was chilled and the precipitate collected on a filter. It was dissel ve'd-irl -warm ethanol, and the ethanol solution was then chilled. The desired dye separated asfiuffiy recl=v needles: meltii-igv at 134-" C. It sensitized a gelatino si -l ver chloride emulsion; with a maximum at 510:

Example 21-12 (3 ethylbenzoxazole) 31.1 (3- methyZ-'- 2 thio i 2,5"(3',4) thiazoledionwl iiimerhmemerocyanine aminewere heated under reflux for 30 minutes'on a steam bath. The reaction mixture was chilled, and the precipitate collected. on a filter;

upon cooling. the solution the desired dye separated as red fluffy needles melting at 270-271" C.

It sensitized a gelatino-silver' chloride emulsion with a maximum at 520 m and a gelatino-silwr bromide emulsion with a maximum at 550 my.

methyl-2-thio-2,5 3,4) -thiaeoledione) cyamne mero- 0113 g. of 3-methyl-2-thio-2,5(3,4)-thiazole- (Home, 1.63 g. of Z-methylthiobenzothiazole meth iodide; 8 cc. of ethanol, and 0.? occur. triethylamineweife heated under reflux for 20 minutes on asteam bath. The reaction mixture. was.

chilled and: the precipitatecollected on a filter. The desired dye was obtained as red prisms melt-- ing at 240 C; on recrystallization from a mixture of benzene and petroleum ether. It sensitized'a,

The precipitate was dissolved in warm benzene, and

tion from pyridine.

mum at 650 m Example 51-[2-(1 -ethylquinline) 1 [4- (3'- methyl-2-thi0-2,5 (3,4) -thiazoZCdione) dimethinemerocyanine 0.73 g. of 3methyl-2-thio-2,5(3,4)-thiazoledione, 2.22 g. of 2-5-acetanilidovinylquinoline ethiodide, 8 cc. of ethanol, and 0.7 cc. of triethylamine were refluxed together for 20 minutes on a steam bath. The reaction mixture was then chilled, andthe precipitate collected on a filter. The desired dye was obtained by recrystallizing the precipitate from ethanol. It was obtained in the form of dark green needles having a melting point of 2732 l4 C. It. sensitized a gelatinosilver chloride emulsion with a flat maximum .lying between 560 and 590 Ill 1., and a gelatinosilver bromide emulsion with a maximum at 600 Example 6.[2 (3 ethylbenzothiazole) 1 [4-(3- methyl 2 thio 2,5(3,4) thiazoledione)l dimethinemerocyanme This dye was prepared by the same manner as the dye of Example 1 above by replacing the 2-5- acetanilidovinylthiazcline methiodide by a molecularly equivalent amount of 2-,3-acetanilidovinylbenzothiazole ethiodide. The desired dye vwas obtained as lustrous gray needles upon recrystallization from pyridine. It melted at 314 vC., and sensitized a gelatino-silver chloride emulsion with a maximum at 560 m and a gelatinosilver bromide emulsion with a maximum at Example 7.-l2(-3-ethylbe nzoselenazole) [4-( methyl 2 thio 2,5 (3,4) thiazoledionefl dimethinemerocyanine The dye was prepared in the same manner as the dye of Example 1 by replacing the 2-;8-acetanilidovinylthiazoline methiodide by a molecularly equivalent amount of 2-B-acetanilidovinylbenzoselenazole ethiodide. The desired dye was obtained as dark gray prisms upon recrystalliza It melted at 308 C'., and sensitized a gelatino-silver chloride emulsion with a maximum at 570 my and a gelatino-silver'bromide emulsion with a maximum at 600 my.

Example 8.--[4-(1-ethylquinoline) [4- (Ii-methyl2-thio-2,5 (3,4) -thiazoledione) dimethinemerocyanine This dye was prepared in the same manner as the dye of Example 1 by replacing the 2-3- acetanilidovinylthiazoline methiodide with a molecularly equivalent amount of Z-B-acetanilidovinylquinoline ethiodide. The desired dye was obtained as dark gray prisms ,upon recrystallization from a mixture of pyridine and diethyl ether. It melted at 2&2 C., and sensitized a gelatino-silver bromide emulsion with a maximum at 640 m 7 Example 9.[2 (3 ethylbenzothz'azole) [4-(3- ethyl-Z-thio 2,5 (3,4) thiazoledionefl tetramethznemerocyanine o=os I C=CH--0H=CHCH=([3 t=s N This dye was repared in the samemanner as the dye of Example 1 by replacing the 2-5- acetanilidovinylthiazoline methiodide with a mo lecularly equivalent amount of Z-(E-acetanilido- 1,3-butadienyl) benzothiazole ethiodide and the 3-methyl-2-thio-2,5(3,4) thiazo1edione by a molecularly equivalent amount of 3-ethyl-2-thio- 2,5(3,4=) thiazoledione. The desired dye was obtained as a blue-gray powder upon recrystallization from methanol. It melted at 208 C. and sensitized a gelatino-silver bromide emulsion with a maximum at 700 m Example 10.-[2-(3-methylbenzothiazole) [4-(3- ethyl-2-thio-2,5 (3,4) -thiazoledz'one) l merocyanine I CH3 CaHs This dye was prepared in the same manner as the dye of Example 3 by replacing the 3-methy1- 2-thio-2,5(3,4) -thiazoledione by a molecularly equivalent amount of 3-ethyl-2-thio-2,5(3,4) thiazoledione. The desired. dye was'obtained in the form of long red needles with a green reflex upon recrystallization from ethanol. It melted at 176 C. and sensitized a gelatino-silver chloride emulsion with a maximum at 450 m l.

Example 11 ..[2-(3 ethylbenzothiaeole) l [4-(3- cycZoheLryl-Z-thio-Zfi(3,4) -thiaeoleclione) tetramelhinemerocyanine' .precipitates collected on a filter.

r This dye was prepared in the same manner as the dye of Example 1 by replacing the 218- acetanilidovinylthiazoline methiodide with a molecularly equivalent amount of 2-(6-acetanilido- 1,3-butadienyl) benzothiazole ethiodide, and the 3-methyl-2-thio-2,5(3,4)-thiazoledione by a molecularly equivalent amount of 3-cyclohexyl-2- thio-2,5(3,4) -thiazoledione. The desired dye was obtained in the form of a dark green, microcrystalline powder upon recrystallization from a mixture of chloroform and petroleum ether. It melted at 228 C., and sensitized a gelatino-silver bromide emulsion with a flat maximum lying between 650 and 740 m The dimethinemerocyanine dyes in the following examples were prepared by refluxing on a steam bath for 20 minutes a mixture of 0.005 mol. of the 2-p-acetanilidovinylcyclammonium quaternary salts of Formula II and 0.005 mol. of the -3-alkyl-2-thio-2,5 (3,4) -thiazolediones of Formula III shown in the examples in the presence of 8 cc. of ethanol and 0.7 cc. of triethylaminee The reaction mixtures were then chilled and the respective The dyes were then recrystallized from the solvents shown in the examples. The appearance and melting point of the dyes are also given in the examples.

Example 12.--[2 (3 ethylbenzoatazolefl [4- (3 ethyl 2,5 (3,4 thz'aeoledione) dlmethinemerocyanine i C2115 C2185 Intermediate of Formula II: z-p-acetanilidovinylbenzoxazole ethiodide. Intermediate of Formula III: 3-ethyl-2-thio-2,5-

(3,4) -thiazoledione.

Recrystallizing solvent: Benzene/petroleum ether mixture.

Appearance of dye: Maroon needles.

Melting point: 228 C.

This dye sensitized a gelatino-silver chloride emulsion with a maximum at 520 m and a gelatino-silver bromide emulsion with a maximum at 560 mp.-

Example 13.[2-(3-ethylbenzothiaeole)l [4-(3- ethyl-Z-thio 2,5(3,4) -thiazoledione) l dimethinemerocyanine Intermediate of Formula II: 2-;8-acetanilidovinylbenzothiazole ethiodide.

Intermediate of Formula III: 3-ethyl2-thio-2,5-

3,4) -thiazoledione. Recrystallizing solvent:

ether mixture. Appearance of dye: Metallic, gray-brown leaflets. Melting point: 255 C.

This type sensitized a gelatino-silver chloride emulsion with a maximum at 570 m and a gelatino-silver bromide emulsion with a flat maximum between 570 and 600 m chloroform petroleum Example 14.--[2-(1-ethyl p naphthothiaaoleJ] [4 (3 ethyl 2 thio 2,5(324) thiazoledione) 1 dimethinemerocyanine Intermediate of Formula II: Z-p-acetanilidovinyl-p-naphthothiazole ethiodide. Intermediate of Formula III: 3-ethy1-2-thio-2,5- (3,4) -thiazoledione. Recrystallizing solvent: Pyridine. Appearance of dye: Fine, gray-green prisms. Melting point: 281 C.

This dye sensitized a gelatino-silver chloride emulsion with a maximum at '590 m Example 15.--[.2 (3 ethylthiazolinefl [4 (3- ethyl 2 thio 2,5(3,4) thiazoledionefl dimethz'nemerocyam'ne Example Iii-[2 (3 ethylbenzoselenazolefl [4 (3 ethyl 2 thz'o 2,5(3,4) thiazo lediomeH dimethz'nemerocyanine 0=C- s A I C=CH-CH= o=s N J7me (137m Intermediate of Formula II: Z-fl-acetanilidovinylbenzoselenazole ethiodide. Intermediate of Formula III: 3-ethyl-2-thio-2,5-

(3,4) -thiazoledione.

Recrystallizing solvent: Pyridine/petroleum ether mixture.

Appearance of dye: Olive-green needles.

Melting point: 234 C.

This dye sensitized a gelatino-silver chloride emulsion with a maximum at 580 me, and a gelatino-silver bromide emulsion with a fiat maximum lying between 580 and 620 m Example 17.-(2'- (1 ethylquinolinefl [4 (3- ethyl 2 thio 2,5 (3,4) thzazoledioneH dimethinemerocyanine Intermediate of Formula II: 2-fi-acetanilidovinylquinoline ethiodide.

:3; intermediate of Formula III: 3-ethyl-2-thio- 2,5 (3,4) -thiazo1edione.

Recrystallizing solvent: Benzene/petroleum ether mixture.

Appearance of dye: Yellow-green plates.

Melting point: 241 C.

This dye sensitized a gelatino-silver chloride emulsion with a maximum at 580 mil and a gelatino-silver bromide emulsion with a maximum at 620 my.

Example 18.[2 (3 methylthiazoline) [4 (3 ethyl 2 thio 2,5 (3,4) thiazoZedz'oneH dimethinemerocyanine Intermediate of Formula II: Z-B-acetanilidovinylthiazoline methiodide. Intermediate of Formula III:

2,5 (3,4) -thiazoledione. Recrystallizing solvent:

ether mixture. Appearance of dye: Deep pink powder. Melting point: 230 C.

This dye sensitized a gelatino-silver chloride emulsion with a maximum at 510 m, and a gelatino-silver bromide emulsion with a maximum at 540 my Eazample 19.-[2 (3 ethylbenzoscazole) [4 (3 cycloheasyl 2 thio 2,5(3,4) thiazole dione) ldimethinemerocyamne 3-ethyl-2-thiochloroform/petroleum Example 20.-[2 (3 ethylbenzothiazolefl -f [4 (3 cyclohexyl 2 thio 2,5(3,4) thz'a zoledione) ldimethinemerocyanine Intermediate of Formula II: 2-15l-acetanilidovinylbenzothiazole ethiodide.

Intermediate of Formula III: 3-cyclohexyl-2 tine-2,5 (3,4) -thiazoledione.

1 Q Recrystallizing solvent: Benzene/petroleum ether mixture. Appearance of dye: Bright green prisms. Melting point: 217 C.

This dye sensitized a gelatino-silver chloride emulsion with a maximum at 560 m and a gelatino-silver bromide emulsion with a maximum at 590 mp Example 21.[2 (3 methylthiazolineHM (3 cyclohexyl 2 thio 2,5(3,4) thiazoledi one) ldimethz'nemerocyanine s 0=o--s :3 c=cn-on=t' t=s lHa (IT/ 13 H20 CH: Ha 5H2 1%.

Intermediate of Formula II: 2-p-acetanilidovinylthiazoline methiodide.

Intermediate of Formula III: 3-cyclohexyl-2- thio-2,5 (3,4) -thiazoledione.

Recrystallizing solvent: Pyridine/petroleum ether mixture.

Appearance of dye: Maroon needles.

Melting point: 306 C.

This dye sensitized a gelatino-silver chloride emulsion with a maximum at 500 m and a gela-.

tine-silver bromide emulsion with a maximum at 530 my.

Example 22.[2 (3 ethylthiazoline) [4 (3 cyclohemyl 2 thio 2,5(8,4) thiazoledi one) ldimethinemerocyam'ne Intermediate of Formula II: 2-p-acetanilidovinylthiazoline ethiodide.

Intermediate of Formula III: 3-cyclohexyl-2-.

thio 2,5 (3,4) -thiazoledione. Recrystallizing solvent: Ethanol/diethyl mixture. Appearance of dye: Turquoise-blue prisms. Melting point: 230-231 C.

This dye sensitized a photographic silver chloride emulsion with a maximum at 500 me and a gelatino-silver bromide emulsion with a maximum at 530 m ether Example 23.-[2- (1-ethylquinoline) [4- (Ii-cyclohexyl 2 thio 2,5 (3,4) thiazoledionefl dimethinemerocyanine Intermediate of Formula II: Z-B-acetanilidovinylquinoline ethiodide.

Intermediate of Formula III: 3-cycl0hexy1-2- thio-2,5 (3,4) -thiazo1edione.

Recrystallizing solvent: Pyridine.

Appearance of dye: Flat gold needles.

Melting point: 264" 0.

Example 24.[-2-(Ii-ethylbenzomaeole) [4- (S-nheptyl' 2 thz'o 2,5 (3,4) thiazoledionell dzmethz'nemerocyanine Intermediate of Formula II: 2-B-acetanilidovinyl benzoxazole ethiodide. Intermediate of Formula III: 3-n-heptyl-2-thio- 2, 5(3,4) -thiazoledione. Recrystallizing solvent: Ethanol. Appearance of dye: Orange-red needles. Melting point: 143 C.

This dye sensitized a gelatino-silver chloride emulsion with a flat maximum lying between 500" and 540 mo, and a. gelatino-silyer bromide emulsion with a maximum at 560 C.

Example 25.--[2 (3 ethylbenzothz'azole)l[4- (3' n heptyl 2 a thio 2,5(3,4) thiazoledione)] dimethinemerocyanine Intermediate of Formula II: Z-fl-acetanilidovinylbenzothiazole ethiodide.

Intermediate of Formula III: S-n-heptyl-2-thio- 2,5 (3,5) -thiazoledione.

Recrystallizing solvent: Ethanol.

Appearance of dye: Gold plates.

Melting point: 156 C.

This dye sensitized a; gelatino-silver chloride emulsion with a maximum at 590 m and a gelatino silver bromide emulsion with a maxi-- mum at 590 my.

Example 26.[2 (3 ethylbenzoselenazole) l [4- (3 nheptyll 2 thio 2,5(3.4) thiazole dione l dimethinmneroc'yanme o=oHoH=( :=s

ExdmpZaZi-[Z 1 ethyl p naphthothlazole) [4 (3 n heptyl' 2 thin-2,58,0- thiazoledz'one)] dimethinemerocyam'ne o=0-s C=CHCH=( l g=s N E Hr-(CHzh-GH;

Intermediate of Formula II: 2-p-acetanili'do-' vinyl-p-naphthothiazole ethiodide. Intermediate of Formula III: 3-n-heptyl-2-thio- 2,5(3A) -thiazoledione. Recrystallizing solvent: Benzene/petroleum ether mixture. Appearance of dye: Green-gold powder. Melting point: 210 C.

This dye sensitized a gelatino-silver chloride emulsion with a maximum at 610 C.

Example .28.[2 (1,3,3 trimethylindolemlne) [4 (3 n heptyl 2 thz'o 2,5(3,4) thiar zoledz'oneH dimethz'nemerocyanine H30 CH3 (13H: oatmeal-ore Intermediate of Formula II: 2-fl-acetanilidovinyl-3,3-dimethylindolenine methiodide.

, Intermediate of Formula III: 3-n-heptyl-2-thio- 2,5 (3,4) -thiazoledione. Recrystallizing solvent: Ethanol. Appearance of dye: Yellow-green needles. Melting point: 117 C.

This dye sensitized both a gelatino-silver chloride emulsion and a gelatino-silver bromide emulsion with a maximum at 580 m Example 29.[2 (3 methylthiaeolz'ne) 1E4 (3- n heptyl -2 thio 2,5(3,4) -thz'azoledione)l dimethz'nemerocyanine Intermediate of Formula II: 2-f3-acetanilidovinylthiazoline methiodide. Intermediate of Formula I-II: S-n-heptyI-Z-thio- 2,5(3A) -thiazoledione. Recrystallizing solvent: Ethanol. Appearance of dye: Pale green needles. Melting point: 119C.

This dyesensitized both-a gelatino-silver chloride emulsion and a gelatino-silver bromide emulsion with a maximum at 530 Ill .4.

Example 30.-[ 2 (3 ethylthzazolz'ne) 1E4 (3- methyl 2 thio 2,5(3,4) thiazoledionefl dimethinemerocyanine Hr-(CHa) 5-GH:

Intermediate of Formula II; 2-B-acetanilidovinylthiazoline ethiodide.

13 Intermediate of Formula III: 3-methyl-2-thio- 2,5 (3,4) -thiazoledione. Recrystallizing solvent: Benzene/petroleum ether mixture. Appearance of dye: Glittering chocolate needles. Melting point: 216 C.

This dye sensitized both a gelatino-silver chloride emulsion and a gelatino-silver bromide emulsion with a maximum at'530 m Example 31.[2.- (1,3,3 trimethylindoleniriefl [4 (3 methyl 2 thio' 2,5(3,4) thiazoledine l dimethinemerocyanine HI CH! o=o--s c=o n-on: =3

HS (EH:

Example 32.--3-ethyZ-2-thio 2,5(3,4) thiazoledione- 18.3 cc. of a 33 percent (by weight) solution of ethylamine in ethanol were added to 10 cc. of methanol. To this solution there was added a solution of 5.7 g. of glycolonitrile in 10 cc. of methanol. The reaction mixture was allowed to stand for 24 hours at room temperature, and the ethanol and methanol removed under vacuum.

The product was distilled off at 41-42 C./3 mm.

There were thus obtained 5.0- g. (49 percent of theoretical) of ethylaminoacetonitrile.

33.0 g. of ethylaminoacetonitrile obtained as described above were dissolved in 50 cc. of methanol. The solution was cooled in an ice-bath, and the air in the flask displaced with an atmosphere of nitrogen. A solution of 30.0 g. of carbon disulfide in 50 cc. of methanol was slowly added, and the reaction mixture allowed to stand for 30 minutes. It was then poured into 400 cc. of 4N-hydrochloric acid and shaken vigorously for 5 minutes. The desired 3-ethyl-2-thio-2,5(3,4)- thiazoledione separated as a yellow solid melting at 63 C. The yield amounted to 38.0 g., or 60 percent oi the theoretical.

1 4 Example 33.-3

' thiazoledz'one N LE A solution of 51.0 g. of cyclohexylamine 50 cc. of methanol was added to a solution of 29.0 g. of glycolonitrile in 50 cc. of methanol. The reaction mixture was allowed to stand at room temperature for 24 hours. The methanol was then distilled off under a vacuum, and the product distilled off at 74-86" C./1 mm. There were thus obtained 65 g. of cyclohexylamino acetonitrile. It had a melting point of 18C.

A solution of 6.9 g. of cyclohexylaminoacetonitrile in 10 cc. of methanol was cooled in an ice bath, and the air in the flask displaced with. nitrogen. A solution of 3.8 g. of carbon disulfidein 5 cc. of methanol was slowly added, and the solution allowed to stand for 30 minutes. The reaction mixture was poured into 60 cc. of 4N- hydrochloric acid, shaken vigorously for 5 minutes, and then chilled. The precipitate was collected on a filter. The desired product was obtained as a solid melting at 114 C.

Emample'34a.3 n heptyl 2 thio 2,5(3,4'

thiazoledione o=o-s A solution of g. of'n-heptylamine in 50 cc. of methanol was added to a solution of 45 g. of

glycolonitrile in 50 cc. of methanol, and the re action mixture allowed to stand at room tem-i The methanol was then removed under vacuum, and the residue distilledat 104-107 C./14 mm. to give g. of n-heptyl-j perature for 24 hours.

aminoacetonitrile.

A solution of 15.4 g. of n-heptylaminoacetonitrile in 30 cc. of methanol was chilled in an ice-bath and the air in the flask displaced with nitrogen gas. A solution of 7.6 g. of carbon disulfide in 30 cc. of methanol was slowly added,

and the reaction mixture allowed to stand for 30 minutes. It was then poured into 100 cc. of IN-hydrochloric acid, shaken vigorously for 5 minutes, chilled, and filtered. The desired prod uct was obtained as a waxy solid.

Example 34b.-3-n-heptyl-2-thio'-2,5 (3,4) thiazoledione-altemate method 47.0 g. of n-heptylaminoacetonitrilewere dripped into an ice-cold mixture of 8.1 cc. of concentrated sulfuric acid in 70 cc. of ethanol 5 cycloheacyl 2 thio 2.56.4)

gamete pended in methanol and then neutralized to phenolphthalein with sodium methoxide. The sodium sulfate formed was filtered ofi and the alcohol removed from the filtrate. The free base, n-heptylglycineamide, slowly solidified, and was recrystallized from ligroin as glossy plates (30.0 g.) having a melting point of 52 C. This product was dissolved in 50 cc. of methanol, the solution cooled in an ice bath, and 13.5 g. of carbon disulfide added. The desired 3 n-heptyl2-thio ,5(31,4)-thiazoledione separated as a solid melting at 115 C. It weighed 27.0 g. and could not be recrystallized without decomposition.

The followmg method in addition to that described" above was found to be advantageous for the preparation of merocyanine dyes from the product of Example 3417.

- 1.37 g. of phosphorustrichloride were added to 2.4 g. of the solid obtained in Example 341) in 12 cc. of dry benzene. The mixture was heated on a steam bath for 10 minutes with good mixing. To the resultant gel were added 24 cc. of ethanol, 4 cc. of triethylamine and 0.01 mol. of one of the intermediates of Formula II above. The solution was heated on a steam bath for 15 minutes, and all solvent removed under reduced pressure. The resultant dye was then extracted from the residue with ethanol. The solution was then'chilled and the dye collected on a filter.

By replacing the amines of Examples 32-3411 by other amines, such as n-propylamine, isopropylamine, n-butylamine, isobutylamine, n-amylamine, n-octylamine, cyclopropylamine, cyclobutylamine, cyclopentylamine, etc. other intermediates coming within the scope of Formula III above can be prepared.

We have found that our new dyes spectrally sensitize photographic silver halide emulsions when incorporated therein. The dyes are especially useful for extending the spectral sensitivity of the customarily employed gelatinosilver-chloride, gelatino-silver chlorobromide, gelatino silver bromide and gelatino silver Ebromiodide developing-out emulsions. To pre-- pare emulsions sensitized vn'th one or more of our newdyes, it is only necessary to disperse. the dye or dyes in the emulsions. The methods of incorporating dyes in emulsions are simple I and are known to those skilled in the art. In practice, it is convenient to add the dyes to the emulsions in the form of a solution in an appropriate. solvent. Methanol or acetone has. proved satisfactory as a solvent for most of our new dyes. Where the dyes are quite insoluble in methyl alcohol, a mixture of acetone and pyridine is advantageously employed as a solvent. The dyes are advantageously incorporated in the finished, washed emulsions and should be uniformly distributed throughout the emulsions. *The particular solvent used will, of course, depend on the. solubility properties of the particular dye.

The concentration of the dyes in the emule sions can vary widely, e. g;. from 5 to 100 .mg. per liter of fiowable emulsion. The concentrate tion of the dyes will vary according to the type or emulsion and according to the efiect desired.

suitable and most economical concentra.- tion for any: given emulsion will be apparent to those skilled in. the art, upon making the: ordinary tests and observations customarilyused in the art or emulsion making. To prepare a gelatinosilver-halide emulsion with one or more of our new dyes. the. tollcwing pro"- cedure is satisfactory:

A quantity of dye is dissolved in methyl aloehol or acetone (or a mixture of acetone and pyridine) and a volume of this solution, which may be diluted with water, containing from 5 to mg. of dye, is slowly added to about 1000 cc. of gelatino-silver-halide emulsion, with stirring. Stirring is continued until the dye is thoroughly dispersed in the emulsion.

With most of our dyes, from 10 to 20 mg. 0 dye per liter of gelatino-silver-bromide or bromiodide emulsion (containing about 40- g. of silver coated on suitable supports, such as glass, cellulose derivative film, resin film or paper in the usual manner.

What we claim as our invention and'desire secured by Letters Patent of the United States is:

1. A merocyanine dye selected from those represented by the following general formula:

o=o- -.s. R-N :o11=on I c =LL- H=c J =s wherein R and R1 each represents an alkyl group containing from 1 to 8 carbon atoms, L represents a methine group, n represents a. positive integer from '1 to 2, n? represents a positive integer from 1 to 3, and Z represents the non-metallic atoms necessary to complete a heterocyclic nucleus selected from the group consisting of those of the thiazole series, those of the benzothiazole series. those of the naphthothi'azole series, those of the thionaphtheno-7,6',4,5-thiazole series, those of the oxazole series, those of the benzoxazole series,

3. The merocyanine dye represented by the rollowing formula:

(. lzHa solvent. However, bathing 4. The merocyanine dye represented by the following formula:

5. The merocyanine dye represented by the fol- 6. The merocyanine dye represented by the following formula:

/ 0=t 3--s ,C=CHCH=C \N/ N 11:55 (JOE-h] 7. A method for making merocyanine dyes comprising condensing a 2-thio-2,5(3,4) -thiazole selected from those represented by the following general formula:

O=C-S wherein R1 represents an alkyl group containing from 1 to 8 carbon atoms with a cyclammonium quaternary salt selected from those having the following general formula:

8. A method according to claim 7 for making merocyanine dyes comprising condensing a 2- thio-2,5(3,4)-thiazoledione with a 2-B-acetanilidovinylquinoline alkyl salt wherein the alkyl group is an alkyl group of the formula CmH2m+1 wherein m represents a positive integer of from 1 to 8.

9. A method according to claim 7 for making merocyanine dyes comprising condensing a 2- thio-2,5(3,4) -thiazoleolione with a 2-,6-acetanilidovinylbenzothiazole alkyl salt wherein the alkyl group is the alkyl group of the formula CmHZm-i-l wherein m represents a positive integer of from 1 to 8.

10. A method according to claim 7 for making merocyanine dyes comprising condensing a 2- thio-2,5(3,4) -thiazoledione with a 2-p-acetanilidovinylnaphthothiazole alkyl salt wherein the alkyl group is the alkyl group of the formula CmH2m+1 wherein m represents a positive integer of from 1 to 8..

11. A method according to claim 7 for makin merocyanine dyes comprising condensing a 2- thio-2,5(3,4) thiazoledione with a 2-p-acetanilidovinylbenzoselenazole alkyl salt wherein the alkyl group is the alkyl group of the formula CmH2m+1 wherein m represents a positive integer of from 1 to 8.

12. A method according to claim 7 for making merocyanine dyes comprising condensing a 3- cycloalkyl-2-thio-2,5(3,4)-thiazole wherein the cycloalkyl group contains from 3-6 carbon atoms in the oycloalkyl ring with a 2-13-acetanilidovinylbenzothiazole alkyl salt wherein the alkyl group is an alkyl group of the formula CmH21n+1 wherein m represents a positive integer of from 1 to 8.

ROY A. JEFFREYS. EDWARD B. KNO'IT.

References Cited in the file of this patent UNITED STATES PATENTS Number Name 7 Date 2,078,233 Brooker Apr. 27, 1937 2,170,804 Brooker Aug. 29, 1939 OTHER REFERENCES Cook, J. Chem. Soc. (1948), pp. 1056 and 1057.

Cook, J. Chem. Soc. (1949) pp. 2342-2346 (part II).

Cook, J. Chem. Soc. (1949) pp. 1435-1437 (part III). 

1. A MEROCYANINE DYE SELECTED FROM THOSE REPRESENTED BY THE FOLLOWING GENERAL FORMULA: 